Home » Intermediate English Grammar » Punctuation


The period is a commonly used signal that a sentence has ended. It is used after two types of sentences: (1) the declarative sentence, which is a statement about something, and (2) the imperative sentence, which is a request or command:

  • Statement: I have five dollars in my pocket.
  • Command: Give me the five dollars that you have in your pocket.

The period is also used after an abbreviation. Some abbreviations are titles: Mr., Mrs., Ms., Dr., Rev. Others are short versions of specific expressions: A.M., P.M., etc. If you end a sentence with one of these abbreviations, do not add a second period. For example:

  • Phillip arrived at exactly 8:00 P.M.

The question mark at the end of a sentence signals that the sentence is asking a question. You already know how to position verbs to form a question. Some examples:

Carlotta is at home.Is Carlotta at home?
You have a problem.Do you have a problem?
They were in Rome.Were they in Rome?

The exclamation point at the end of a sentence signals that the information in the sentence is stated strongly or with emotion. Some ordinary statements and exclamations look identical. But if the sentence ends in an exclamation point, it is expressed with emotion:

Ordinary StatementStrong Statement
Jason is sick.Jason is sick!
I saw a stranger there.I saw a stranger there!
It has started to snow.It has started to snow!
He didn’t leave.He didn’t leave!

The comma is the signal in the middle of a sentence that ideas are being separated. This can be done to avoid confusing the ideas or to separate things in a list. For example, compare the sentence “When he came in the house was cold.” to “When he came in, the house was cold.” You do not mean that “he came in the house.” There are two ideas here in two clauses. They are separated by a comma: (1) He came in. (2) The house was cold.

As an example of a list, consider the sentence “He bought pop, tarts, and candy.” If you omit the comma after pop, someone might think that he bought pop tarts.

In a list, there should be a comma after every item until you use the word anda boya girltwo dogs, and a cat. Some English writers prefer to omit the comma before and.

  • I need paint, brushes, a yardstick, and some tape.
  • OR
  • I need paint, brushes, a yardstick and some tape.

Commas are also used to separate the name of a person to whom an imperative or a question is directed:

  • Janelle, call Mr. Montoya on the telephone.
  • Dr. Gillespie, will my husband be all right?
  • Boys, try to be a little quieter.

They are also often needed to separate two or more adjectives that modify a noun:

  • She wore a red, woolen jacket.
  • The tall, muscular man was a weightlifter.

You should use a comma to separate two independent clauses combined as a compound sentence. They are most often combined with these conjunctions: andbutfornotorso, and yet. An independent clause is one that has a subject and predicate and makes sense when it stands alone. Some examples:

  • DeWitt is baking a cake, and Allison is preparing the roast.
  • Do you want to go to a movie, or should we just stay home?
  • It began to rain hard, yet they continued on the hike.

You should separate exclamations and common expressions from the rest of the sentence with a comma:

  • Oh, I can’t believe you said that!
  • No, I don’t live in Germany anymore.
  • Yes, you can go outside now.
  • Well, you really look beautiful tonight.
  • By the way, my mother is coming for a visit.

A comma is required to separate the day of the week from the date, and the day of the month from the year. The comma is omitted if only the month and year are given.

  • He arrived here on Monday, June 1st.
  • My birthday is January 8, 1989.
  • The war ended in May 1945.

decimal point looks like a period. In some languages, a decimal amount is separated by a comma: 6,25 or 95,75. But in American English, a decimal amount is separated by a period (a decimal point): 6.25 or 95.75.

In long numbers, amounts of thousands are separated by a comma in English. In other languages, they are often separated by a decimal point or by leaving a space:

English NumbersNumbers in Other Languages
1,550,6001.550.600 or 1 550 600
22,000,00022.000.000 or 22 000 000

The colon signals that a list of things or special related information follows. For example:

  • You’ll need certain tools for this project: a hammer, screwdriver, hacksaw, and chisel.
  • I suddenly understood the plot of the story: A man steals a thousand dollars to help his dying son.

It is also used to separate the hour from the minutes when telling time: 5:30, 6:25 A.M., 11:45 P.M.

The semicolon is a punctuation mark that is similar to both a comma and a period. It signals that there is a pause between ideas, and those ideas are closely linked. It often combines two related independent clauses into one sentence:

  • Jamal is a powerful runner; he is determined to win the race today.
  • Loud music filled the room; everyone was dancing as if entranced.

Quotation marks enclose the words that are said by someone. They indicate a direct quote. Look at the difference between a direct and indirect quote:

Direct QuoteIndirect Quote
He said, “Stay where you are.”He said that I should stay where I am.
She asked, “Is that Tran’s brother?”She asked if that is Tran’s brother.

Remember that all punctuation marks that belong to the quoted sentence are enclosed inside the quotation marks:

  • Correct: He asked, “Does she often visit you?”
  • Incorrect: He asked, “Does she often visit you”?

The title of a short story or magazine article should be enclosed by quotation marks: I just read “My Life on a Farm” by James Smith. If a quote is located within a quote, it should be enclosed by single quotation marks: He said, “I just read ‘My Life on a Farm’ by James Smith.”

You already know that the apostrophe is used in forming contractions:

  • I am → I’m
  • we are → we’re

The apostrophe is also used to form possessives. To make the meaning of a singular noun possessive, add -’s. For plural nouns that end in an -s, just add the apostrophe. All other plurals will end in -’s.

NounPossessive FormMeaning
boythe boy’s dogthe dog that belongs to the boy
boysthe boys’ gamesthe games that belong to the boys
housethe house’s roofthe roof of the house
TomTom’s auntan aunt of Tom’s
booka book’s pagesthe pages of a book
menthe men’s workthe work that the men do

If a word ends in an -s, you can add -’s to form the possessive when the pronunciation of the word requires another syllable in the possessive:

  • Lois → Lois’s
  • Thomas → Thomas’s
  • actress → actress’s

If another syllable is not pronounced to form the possessive, just add an apostrophe; this tends to be the case in the plural:

  • actresses → actresses’
  • railings → railings’
  • classes → classes’

It is common to use an apostrophe to form the plural of abbreviations: two Dr.’sthree M.D.’sfour Ph.D.’s. The same is true when forming the plural of a number or letter: “You had better mind your p’s and q’s.”

Leave a Comment

error: Alert: Content is protected !!